There are two basic types of dulcimer stringed musical instruments, the Appalachian or mountain dulcimer and the hammered dulcimer. The Appalachian dulcimer is a fretted string instrument of the zither family, typically with three or four strings. The body extends the length of the fingerboard, and its fretting is generally diatonic.
As with guitars, mandolins, and banjos, some musicians would like to use a capo on a fretted dulcimer to shorten the playable length of the strings, thereby raising the pitch. There are several dulcimer capos on the market, some of which are quick-release. One quick-release design is described in U.S. Pat. No. 5,373,770. According to this patent, the top and one side of a U-shaped body are attached together in a perpendicular orientation while the other side of the U-shaped body is in a perpendicular relationship to the top but is movable across the length of the top. The movable side of the capo is adjusted by a thumbscrew and shaft so that the overall length of the capo from side to side may be conformed to the width of the capo fret board in use by adjusting the movable side. Outside the movable end is a quick-attach lever and fastening piece. The sides of the U-shaped capo are adjusted to the width of the raised capo fret board, with the L-shaped lever pulled to the upright position. A non-concentric cam tightens the movable portion of the capo against the side of the raised fret board. Releasing the capo simply requires moving the L-shaped lever into the horizontal position, removing the side pressure of the non-concentric cam. Inside the capo are cushioned pads so that the metal dulcimer capo does not harm the wooden dulcimer fret board.
While the device just described and other designs are certainly functional, a more elegant quick-release mechanism would be welcomed by the dulcimer-playing community.